Shoe last



Nov. 1, 1938. G A SIN 2,135,172

SHOE LAST Filed Feb. 20, 1936 INVEN TOR.

, 4 Geo/g9 C/aus/hy BY F l S. 4 Z I ATORNY Patented Nov. '1, 1938 UNITED STATES SHOE LAST George Glausing, Portsmouth, Ohio, assignor to Vulcan Corporation, Portsmouth, Ohio 7 Application February 20, 1936, Serial No. 64,923

6 Claims;

7 This invention relates to shoe lasts, and is directed particularly to the hinge means which joins the toe and heel parts of the last and which permits relative movement of the last parts and a resultant expansion and contraction of the last as to length.

A shoe last is normally made from a solid block of wood which is expanded into two parts commonly known as fore and back, or toe and heel parts. These parts are joined together by a suitable hinge means which permits of themeessary manipulation of the shoe last in accordance with the well known shoe making practice, namely, collapsing and expanding of the last. 'llhus, the weakest point in the shoe last structure has been at the hinge area where there is a V- shaped cut from the comb of the last downwardly to permit relative rotative movement between the last parts, or collapsing and expanding of the last. When the last parts are in expanded position, there is only a small abutting area between the toe and heel parts, this abutting area being confined to a relatively small bearing surface on which one last part rotates or moves relative to the other and a small abutting area at the bottom of the last which acts as a' stop to prevent relative movement of the last parts past their normal expanded position.

It has been found that there is a tendency for shoe lasts to break at the weakest point, the hinge area, during soling or leveling of a shoe on the last. In making a shoe on the last, the last is inverted, the heel end being supported on a jack pin and the toe being supported adjacent its extreme outer end on some suitable rest. Considerable pressure is exerted on the last throughout its length during these two mentioned operations with a resultant compression force on the last at the unsupported hinge area. This compression places a tension stress on the hinge and a compression stress on the small abutting area between the toe and heel parts and adjacent the bottom of the last, the bottom of the last, as referred to, being uppermost during the process of making a shoe. Such compression force on the bottom of the last tends to pull the last apart at the hinge area and to crush the abutting surface between the toe and heel parts and adjacent the bottom of the last.

One object of this invention is to provide a shoe last which has substantially equal resistance to compression and tension stresses at its hingearea as it has throughout its solid remainder. In accomplishment of this object,

means are provided to prevent abnormal displacement of the toe and heel parts beyond their relative positions when the last is expanded, and, at the same time, means are provided for offsetting the compression andtension forces existing at the hinge area during the leveling, soling and other shoe making operations.

Another object of this invention is to provide a hinge construction for connecting the toe and heel parts of a shoe last which is of a nature to permit the axis of rotation or movement of the one last part relative to the other to be located at a minimum distance above the bottom of the last, whereby rotation of one last part relative to the other in collapsing of the last will produce a maximum contraction or shortening of the last. With this invention, the disposition of the axis of rotation between last parts at an extremely low point with relation to the bottom of the last is accomplished without lessening th strength of the hinge area. 4 I

Various other objects and advantageous features of this invention may be had from the following description, and one embodiment thereof may be seen in the accompanying drawing wherein similar characters of reference designate corresponding parts and wherein:

' Fig. l is a side elevation of a shoe last embodying the invention, the parts adjacent the hinge being broken away to show the hinge parts in elevation, the last being shown in expanded position. a

Fig. 2 is a side elevation of a last with the portion of the last adjacent to the hinge broken away to show the hinge parts in elevation, the last parts being shown in their collapsed or contracted position. i r

'Fig. 3 is a sectional view taken on the line 3-3 of Fig. 2 and showing the hinge.

Fig. 4 is an elevation showing a modification of the stop link used as a part of the hinge construction.

Referring to the drawing, a shoe last is shown which includes the usual toe or fore part I and heel or back part 2 connected together by hinge means which will be presently described. It will be understood that the shoe last is ordinarily made from a solid block of wood, and the fore and back parts I and 2 are later separated by combinedstraight and arcuate cuts to provide a ball like part 3 and a socket A to form a hinge joint between the parts. As shown, the back part 2 is cut away at its upper left hand corner to increase the effective circumferential area of the part 4 and permit the back part 2 to rotate or move relative to thefore part l about'an axis,

this center of movement or rotation being indicated at X. Such relative movement or rotation of the parts permits the last parts to be collapsed as shown in Fig. 2 to shorten the last length and remove the last from the shoe, or permits the last to be expanded and made longer as shown in Fig. l, in which position the last parts are placed for the making of the shoe. The hinge joint is adjacent the last bottom, as shown, to make this collapsing or expanding possible.

One usual connection between the fore and heel parts of the last takes the form of a spring or tension member 6 disposed in routed out portions 1 in the fore and back parts and attached at one end to the back part and at its other end to the fore part, such member ordinarily being under tension to hold the two last parts together. The connection for the opposite ends of the spring or tension member are disposed oppositely of the hinge joint including the ball like part 3 in the back part and the socket 4 in the fore part, with the spring or tension member crossing such hinge joint. With this arrangement, considering that the back part moves or rotates relative to the fore part about the center X of the hinge joint, as thespring or tension member passes from one side to the other of the axis X it tends to snap the last into its expanded or collapsed position, as the case may be, the spring or tension member being put under greatest tension just as it crosses the axis of movement or rotation of the back part.

In addition to the spring or tension member as a connecting means between the fore and'back parts of the last, two links are ordinarily provided, one on either side of the spring or tension member and connected at their opposite ends to the same pins to which the spring or tension member is connected, the connection between the links and the pins being fitted so as not to interfere with movement of one last part relative to the-other about the axis X. The purpose of these links is to prevent the last parts frombeing pulled apart at the hinge connection when compression is exerted on the bottom of the last during the shoe making operations. The parts of the last if no links were provided, would be connectedtogether solely by the spring or tension member. Such construction of the connecting means between the fore and back parts of the last requires that the hinge joint or ball and socket arrangement or any other axis or rotation between the fore and back parts of the last, be located a considerable distance above the bottom of the last to provide abutting surfaces between the fore and back parts at the bottom of the lastof suificient' area to withstand compression exerted on the bottom of the last during the shoe making operation. At a time when the last is inverted and supported only at or adjacent its opposite ends, this small abutting area adjacent the bottom of the last is the only means provided for preventing movement or rotation of the last parts past theirnormal expanded position. The location of this axis of movement or rotation a substantial distance above the bottom of the last necessarily reduces the amount of shortening of the last brought about by movement or rotation of the back part relative to the fore part in collapsing the last. It is thus desirable that the axis of movement or rotation of the back part relative to the fore part be as near the last bottom as is possible. I

As hereinbefore'stated, the fore. and back parts of the last are routed out to form chambers 1 which are coincident when the last is in collapsed position as shown in Fig. 2. A spring or tension member 6 is disposed in this chamber with one of its ends connected to a transverse pin 8 in the back part and its opposite end connected to transverse pin 9 in the fore part, the spring or tension member 6 being of a shape and the pins 8 and 9 being so located that the spring or tension member crosses the axis of movement or rotation of the back part relative to the fore part during movement of the last parts into collapsed and expanded positions, and is always under tension so as to hold the last fore and back parts together. Such crossing of the spring or tension member across the axis of rotation between the fore and back parts of the last results in a snapping of the parts into their collapsed or expanded positions after the spring or tension member crosses the axis X, the spring or tension member being placed under greatest tension just as it is crossing such axis. As will be noted in the drawing, a link 9' is also disposed in the chamber containing the spring ortension memher 6. However, instead of the link being disposed on the same pins'Band 9-with the spring or tension member and across the axis-Xas previously practiced, the link 9' forms substantially a rectangle and is connected at its upper side; with transverse pins In and H, located above the pins 8 and 9, as well: as being disposed at itslower corners on the pins 8 and 9; As shown, the pins 9 and H are in the fore part of the last, while the pins I0 and 8am in the back part. of the last, the upper part of the link 9 being, connected to the pins I0 and H by means of elon-' gated slots l2 which permit movement of the back and fore partsof the last relative to each other about the hinge to the collapsed position as shown in Fig. 2. The slots permit the last parts to rotate oppositely a certain amount of the expanded'position but present the abutting surfaces; l3 and H. at the bottom of the last from being pushed against each other with a force to crushv either; of the surfaces whenthe last is in anexpanded position and pressure is put on the bottom thereof. As shownin Fig. 3, two links 9' are used,. these links being separated by the-spring 6, although only one link may be used..

During the making of a shoe on a last. of the type shown, the last is turned. upside down from the position shown in-Fig. 1 of the drawing and is supported at one'end by means of a jack pindisposed ina hole 20 provided therefor and at the other end on a suitable support. on which the toe end rests adjacent its extreme end. With the last in this position, the shoe upper. having been placed on a last, what is known as the soling and sole leveling operation takes place. During. these two operations considerable pressure is exerted on the bottom of the last at various points between the two supports, one at eachend of the last. Such pressure tends to spread the last at the hinge connection between the fore and back part, with the greatest compression being exerted at the abutting surfaces l3 and I4 beneath the hinge joint end at the last bottom. It also places a considerable tension stress on'the spring 6,

disposed in a plane having its bottom line acrossfrom the pin 8 to the pin 9 and its top line from the pin l0 tothe pin ll Thus, a series of-lines of resistance are formed, whichare consider ably above the joint formed by the ball portion 3 and depression 4 and by the contacting surfaces l3 and I4. With the link or links 9' so located, compression exerted on the last bottom tending to separate the last at its top and crush the last at itsabutting surfaces l3 and M will be compensated for by the link or links 9 preventing the last from spreading at its top;

-With reference to the lines of resistance in the turning of the last part about the axis X when pressure is exerted on the bottom of the last, it will'be seen that any pressure on the bOttOIIiOf the last tending to rotate the fore and back part about the axis X and cause a crushing of the surfaces I3 and M, will be resisted by the-link or links 9 on a line between the pins l0 and H, as well as on a line between the pin 9 and the pin l0 and on a line between the pin 8 and the pin ll. Thus, three positive lines of resistance are provided which act against any tendency of the last parts to be rotated one about the other on the axis X, due to pressure exerted on the bottom of the last. The line of resistance just described provides a series of lever arms between each of the pins forming the ends of its own particular resistance line and the abutting surfaces 13 and 14 at the bottom of the last. These lever arms are of such length and so disposed that it would take considerably more pressure than that exerted on the bottom of the last during the soling and sole leveling operation to crush the last at or near these abutting surfaces. Thus, it is possible to reduce the area of these abutting surfaces and lower the hinge joints between the last parts more closely to the last bottom.

The possibility of lowering the hinge joint between the last parts at a point closely adjacent the last bottom is .highly desirable in that rela tive rotation of the last parts to a collapsible position as shown in Fig. 2 will result in a quicker and at the same time a greater shortening of the last length, whereby the last may be collapsed and withdrawn from the shoe without danger of stretching or mutilating the shoe which has been built upon the last.

In operation, the fore and back parts of the last are normally in the position as shown in Fig. 1. That is, the last is expanded to the position wherein it has the greatest length, and a shoe is constructed on the last while the parts are in this position. It will be noted that the pins I0 and H are bearing against the outer extremities l6 of the elongated part l2. Thus, it will be seen that the tendency of any pressure exerted on the bottom of the last which tends to spread the last at its top while such last ,is supported at its opposite ends, will be resisted by the link or links 9'. When the last is collapsed as shown in Fig. 2, the pins I0 and II move to the inner extremities of the elongated part 12. Thus, a connection is provided between the fore and back parts of the last, and this connection, while not interfering in any way with the usual collapsing and expanding movement of the last, is much stronger than any heretofore employed and is elfective to prevent the crushing of the abutting surfaces at the bottom of the last when pressure is exerted thereon.

In the present invention, the pressure intensities are reduced to a minimum and the factor of safety of the stop member and pin is sufficiently great to insure that the last will not fail under the most severe break-down tests. It is evident that an even more favorable distribution of forces may arrived at by moving the stop pins I0 and II higher up in the body of the last. Referring to Fig. 4 of the drawing, I have shown a link which is a modification ofthe link.

9"shown in Figs.'l, 2 and 3, the difference being that the link shown in Fig. 4 is adapted to be disposed only on the pins 8, 9 and thy means of openings 16 and the elongated part ll respectively. With this type of link, the'only line of resistance against rotation of the last shown in Fig. 4 is substantially identical with the link shown in Figs. 1, 2 and 3;

What I claim is:

1. A shoelast having a fore and heel part and a hinge there-between to permit expansion and contraction of the last, a spring member tensioned to produce compression at the joint of said hinge and operable to snap the last into expanded and contracted positions, a pair of pins upon which the ends of said spring are anchored, a stop link having an upper section situated above the axis of said hinge and a lower section having apertures within which are received said spring anchor pins, and means in said upper section of the link to permit contraction of the last and to prevent the rotation of the hinge beyond its normal position when the last is expanded.

2. A shoe last having a fore and a heel part and a hinge therebetween to permit expansion and contraction of the last, a spring at said hinge tensioned to produce compressionat the point of said hinge, a pair of anchor pinssecuring the ends of said spring, a pair of stop pins rigidly secured respectively in the fore and heel parts of the last, a. stop member having apertures within which the spring pins are received and a pair of slots situated a substantial distance above the axis of said hinge within which said stop pins are received, said slots being properly spaced relasaid last, a spring member within said chamber 7 operable to snap the last into its expanded and contracted positions, a pair of pins upon which the ends of said spring are anchored, a pair of stop pins situated a substantial distance above the axis of said hinge and a pair of stop members having apertures in their lower portions within which the spring pins are received and a pair of slots in its upper portion within which the said stop pins are received, said slots being properly positioned relatively to said stop pins to cause the outer ends of the slots to engage the pins and pre vent the rotation of said hinge beyond its normal position when the last is expanded.

4. A shoe last comprising a fore part, a heel part, a hinge situated therebetween and closely adjacent to the bottom face of the last, said hinge acting to permit expansion and contraction of the last, a spring member acting to secure the said fore and heel part together and to snap the ing a pair of slots therein and a lower section having apertures within which are received said spring anchor pins, a pair of stop pins situated respectively in the said fore and heel parts and 11),- received within said slots, said slots being spaced relatively to said stop pins to cause the outer ends of the slots to engage the pins when the last is expanded thereby to limit the rotation of said hinge beyond its normal position.

5. A shoe last having a fore and heel part and F a hinge therebetween to permit expansion and contraction of the last, a spring member tensioned to produce compression at the joint of said hinge and operable to snap the last into exgo panded and contracted position, an extensible stop member extending between the heel and fore part of the last, means common to said spring andstop-members for anchoring the ends thereof, an abutment of hard material anchored in the last coacting with said stop member positively to stop all relative movement between the last parts due to a force acting to rotate the parts about.

the hinge axis beyond their normal, relative position when in expanded position, said stop means freely permitting contraction of the last.

6. A shoe last having a fore and heel part and a hinge therebetween to permit expansion and contraction of the last, a link extending between the fore and heel parts of the last and permanently connected to one of the last parts-at one point, and a stop fixed on the other last part inposition to engage the link in a plane including saidpoint of connection and on one side of the axis of the hinge when the last is in its expanded position and. thereby secure the last parts against movement beyond the normal expanded position of the last,

said stop being movable relative to the link to.

permit movement of the last parts to their con- 29' tracted position.

GEORGE CLAUSIN G. 

